SWOLF is an abbreviation for "Swim Golf" and is a score obtained by adding together the number of swim strokes per pool length, and the time it took to swim that length. For instance, 30 seconds and 10 strokes to swim the length of a pool will equal a swolf score of 40. A lower score is better, just as in golf.
The Forerunner 910XT can only utilize swolf when set to Pool Swim within the Swimming sport mode.
For other devices capable of recording an outdoor swim activity using GPS, the SWOLF score will be normalized based on a 25 meter pool. Accuracy of the score will be dependent on the device's ability to record an accurate GPS pace and distance while swimming. Please also note that for outdoor swim activities these devices will only provide a SWOLF score in Garmin Connect. You will not receive a SWOLF graph.